Radiation hormesis

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Radiation hormesis is the hypothesis that modest levels of ionizing radiation are beneficial, stimulating repair mechanisms that protect against diseases.

Radiation hormesis Wikipedia


Low-Dose Radiation Can Enhance Natural Barriers to Cancer, according to the Journal of American Physicians and Surgeons Association of American Physicians and Surgeons (AAPS); CISION PR newswire; 15 Dec 2017

High-dose ionizing radiation is known to reduce the body's resistance to cancer, but low-dose radiation actually enhances natural defenses, writes Bobby R. Scott, Ph.D., in the winter issue of the Journal of American Physicians and Surgeons. This means that the widely believed statement that "there is no safe dose of radiation" is not true.
Scott, a scientist emeritus at the Lovelace Respiratory Research Institute in Albuquerque, N.M., points out in this review that natural background radiation is estimated to have been five-fold higher in earlier eras, and mammals likely survived because of enhanced natural cancer barriers.

Small Radiation Doses Enhance Natural Barriers to Cancer Bobby R. Scott, Ph.D; Journal of American Physicians and Surgeons; Winter 2017

Natural barriers to cancer exist at the molecular, cellular, tissue, organ, and whole-body levels. The cancer barriers are diminished by high radiation doses, facilitating cancer occurrence. In contrast, low radiation doses enhance these cancer barriers, which can lead to threshold and hormetic doseresponse relationships for cancer induction. These facts render the linear-no-threshold (LNT) model for cancer induction implausible.
In earlier eras in geologic time, the level of natural background radiation is estimated to have been about five-fold larger than in recent times.
Mammals likely could not have survived in this harsher radiation environment without the ability to enhance natural protection (barriers) against cancer and other life-threatening diseases.

The Chernobyl Conundrum: Is Radiation As Bad As We Thought? Manfred Dworschak; Der Spiegel; 26 Apr 2016

Who would voluntarily breathe in radioactive gas? These days, there are people who do. They swear by the notorious noble gas radon, created by the decay of uranium: They inhale it deeply. Most believers in the healing qualities of radiation are suffering from a chronic inflammatory disease: arthritis, asthma or psoriasis, for example. The gas, they argue, alleviates their problems for months, which is why they lay in bubbling radon water offered by some healing spas. In Bad Kreuznach, in the German state of Rhineland-Palatinate, brave spa guests even trek into the tunnels of an abandoned mercury mine, attracted by the radon-filled air in the mountain. Are they crazy? As has now become clear, these people are right: Radioactivity is good for them. These are the initial findings of an ongoing large-scale trial conducted by researchers from four German institutes. The leader is radiobiologist Claudia Fournier, from the Helmholtz Center for Heavy Ion Research in Darmstadt.

Radiation Hormesis: Historical Perspective and Implications for Low-Dose Cancer Risk Assessment Alexander M. Vaiserman; Dose-Response; 18 Jan 2010

Current guidelines for limiting exposure of humans to ionizing radiation are based on the linear-no-threshold (LNT) hypothesis for radiation carcinogenesis under which cancer risk increases linearly as the radiation dose increases. With the LNT model even a very small dose could cause cancer and the model is used in establishing guidelines for limiting radiation exposure of humans. A slope change at low doses and dose rates is implemented using an empirical dose and dose rate effectiveness factor (DDREF). This imposes usually unacknowledged nonlinearity but not a threshold in the dose-response curve for cancer induction. In contrast, with the hormetic model, low doses of radiation reduce the cancer incidence while it is elevated after high doses. Based on a review of epidemiological and other data for exposure to low radiation doses and dose rates, it was found that the LNT model fails badly. Cancer risk after ordinarily encountered radiation exposure (medical X-rays, natural background radiation, etc.) is much lower than projections based on the LNT model and is often less than the risk for spontaneous cancer (a hormetic response). Understanding the mechanistic basis for hormetic responses will provide new insights about both risks and benefits from low-dose radiation exposure.

The Cancer Risk From Low Level Radiation: A Review of Recent Evidence Bernard L. Cohen; Hacienda Publishing; Jul/Aug 2000

This article deals with an aspect of the biological science underlying health risk analysis. Many vitamins and minerals have been known to promote health in small doses and cause disease in high doses for some time. Accumulating evidence indicates that ionizing radiation and other agents also interact with biological systems in similar fashion. The phenomenon is called "hormesis." Hormesis is now being considered as a general biological phenomenon (e.g., cf. Linda M. Gerber, George C. Williams and Sandra J. Gray, "The Nutrient-Toxin Dosage Continuum in Human Evolution and Modern Health," Sept. 1999, The Quarterly Review of Biology, Vol. 74, No. 3, pp. 273-289.)
Prof. Cohen reviews some of the accumulating evidence about biological responses to ionizing radiation. The theoretical and practical implications of this evidence are life-threatening and life-saving. For example, if ionizing radiation exposure is over-regulated, individual and societal resources are wasted in attempts to reduce harmless or even healthful radiation exposure dosages. These wasted resources would be better applied to improving the conditions of human life. Wasted resources kill.
Radiation protection regulators often claim that they try to err on the side of caution. But in doing so, regulators in the past have ignored the evidence of hormesis in response to ionizing radiation. To look at only the bad effects of radiation and be blind to the good effects is comparable to banning penicillin based on the fact that penicillin can kill by anaphylaxis while ignoring lives saved by the substance.
In addition to harming peoples' health, public health policies based on incomplete evaluation of scientific evidence harm the reputation of science in the mind of the public. Science and the public reputation of science advance only when all pertinent evidence is considered.

Shifting the Paradigm in Radiation Safety Mohan Doss; Dose-Response; Feb 2012

The current radiation safety paradigm using the linear no-threshold (LNT) model is based on the premise that even the smallest amount of radiation may cause mutations increasing the risk of cancer. Autopsy studies have shown that the presence of cancer cells is not a decisive factor in the occurrence of clinical cancer. On the other hand, suppression of immune system more than doubles the cancer risk in organ transplant patients, indicating its key role in keeping occult cancers in check. Low dose radiation (LDR) elevates immune response, and so it may reduce rather than increase the risk of cancer. LNT model pays exclusive attention to DNA damage, which is not a decisive factor, and completely ignores immune system response, which is an important factor, and so is not scientifically justifiable. By not recognizing the importance of the immune system in cancer, and not exploring exercise intervention, the current paradigm may have missed an opportunity to reduce cancer deaths among atomic bomb survivors. Increased antioxidants from LDR may reduce aging-related non-cancer diseases since oxidative damage is implicated in these. A paradigm shift is warranted to reduce further casualties, reduce fear of LDR, and enable investigation of potential beneficial applications of LDR.


Treatment of Alzheimer Disease With CT Scans - A Case Report Jerry M. Cuttler, Eugene R. Moore, Victor D. Hosfeld, David L. Nadolski; Dose-Response; 2016

This case report describes the remarkable improvement in a patient with advanced AD in hospice who received 5 computed tomography scans of the brain, about 40 mGy each, over a period of 3 months. The mechanism appears to be radiation-induced upregulation of the patient’s adaptive protection systems against AD, which partially restored cognition, memory, speech, movement, and appetite.


Background radiation and cancer incidence in Kerala, India-Karanagappally cohort study Nair RR, Rajan B, Akiba S, Jayalekshmi P, Nair MK, Gangadharan P, Koga T, Morishima H, Nakamura S, Sugahara T.; Health Physics; Jan 2009

Although the statistical power of the study might not be adequate due to the low dose, our cancer incidence study, together with previously reported cancer mortality studies in the [High Background Radiation] area of Yangjiang, China, suggests it is unlikely that estimates of risk at low doses are substantially greater than currently believed.

What can we learn from Kerala Geoff Russell; Brave New Climate blog; 24 Jan 2015

Kerala has a very high rate of background radiation due to sands containing thorium. The level ranges from about 70 percent above the global average to about 30 times the global average. For thousands of years, some of the population of Kerala have been living bathed in radiation at more than triple the level which will get you compulsorily thrown out of your home (evacuation) in Japan. The Japanese have set the maximum annual radiation level at 20 milli Sieverts per year around Fukushima while some parts of Kerala have had a level of 70 milliSieverts per year … for ever.
Scientists have been looking for radiation impacts on Keralites (people from Kerala) for decades. In 1990 a modern cancer registry was established and in 2009 a study reported on the cancer incidence in some 69,958 people followed for an average of over a decade. Radiation dose estimates were made by measuring indoor and outdoor radiation exposure and time spent in and out of doors. They haven’t just been bathing in radioactivity for thousands of years, Keralites have been eating it. An early 1970 study found that people in Kerala were eating about 10 times more radioactivity than people in the US or UK, including alpha particle emitters (from fish).
The cancer incidence rate overall in Kerala is much the same as the overall rate in India; which is about 1/2 that of Japan and less than 1/3rd of the rate in Australia. Some 95 new cancers per 100,000 people per year compared to 323 per 100,000 per year in Australia (age standardised).
Cancer experts know a great deal about the drivers of these huge differences and radiation isn’t on the list.
The Kerala study has several advantages over other studies of low dose radiation. They are dealing with a mainly rural population which is less likely to be exposed to other carcinogens which could complicate the analysis. They are also dealing with a genuinely low rate of radiation exposure. This mirrors what would be the case in Fukushima if the Government hadn’t forcibly moved people. Most radiation protection standards derive from studies of atomic bomb victims who got whatever dose they got in a very short time. They may have got a dose which fits the definition of low (less than 100 millisieverts), but at an extremely rapid rate. Getting bombed just isn’t like living in a slightly elevated radiation field. In Kerala people are getting a low rate for a long time.


VERY HIGH BACKGROUND RADIATION AREAS OF RAMSAR, IRAN: PRELIMINARY BIOLOGICAL STUDIES Ghiassi-nejad, M., Mortazavi, S. M. J., Cameron, J. R., Niroomand-rad, A., Karam, P. A.; Health Physics; Jan 2002 [paywalled]

People in some areas of Ramsar, a city in northern Iran, receive an annual radiation absorbed dose from background radiation that is up to 260 mSv y−1, substantially higher than the 20 mSv y−1 that is permitted for radiation workers. Inhabitants of Ramsar have lived for many generations in these high background areas. Cytogenetic studies show no significant differences between people in the high background compared to people in normal background areas. An in vitro challenge dose of 1.5 Gy of gamma rays was administered to the lymphocytes, which showed significantly reduced frequency for chromosome aberrations of people living in high background compared to those in normal background areas in and near Ramsar. Specifically, inhabitants of high background radiation areas had about 56% the average number of induced chromosomal abnormalities of normal background radiation area inhabitants following this exposure. This suggests that adaptive response might be induced by chronic exposure to natural background radiation as opposed to acute exposure to higher (tens of mGy) levels of radiation in the laboratory. There were no differences in laboratory tests of the immune systems, and no noted differences in hematological alterations between these two groups of people.

Taiwan / Cobalt 60

Effects of cobalt-60 exposure on health of Taiwan residents suggest new approach needed in radiation protection. Chen WL, Luan YC, Shieh MC, Chen ST, Kung HT, Soong KL, Yeh YC, Chou TS, Mong SH, Wu JT, Sun CP, Deng WP, Wu MF, Shen ML; Dose Response (publication of international Hormesis society); 25 Aug 2006

Approximately 10,000 people occupied [] buildings [contaminated with Cobalt-60] and received an average radiation dose of 0.4 Sv, unknowingly, during a 9-20 year period. They did not suffer a higher incidence of cancer mortality, as the LNT theory would predict. On the contrary, the incidence of cancer deaths in this population was greatly reduced-to about 3 per cent of the incidence of spontaneous cancer death in the general Taiwan public. In addition, the incidence of congenital malformations was also reduced--to about 7 per cent of the incidence in the general public. These observations appear to be compatible with the radiation hormesis model.

30 years follow-up and increased risks of breast cancer and leukaemia after long-term low-dose-rate radiation exposure Wan-Hua Hsieh, I-Feng Lin, Jung-Chun Ho, Peter Wushou Chang; British Journal of Cancer; 3 Oct 2017

The current study followed-up site-specific cancer risks in an unique cohort with 30 years’ follow-up after long-term low-dose-rate radiation exposure in Taiwan.
Dose-dependent risks were statistically significantly increased for leukaemia excluding chronic lymphocytic leukaemia (HR100mSv 1.18; 90% CI 1.04–1.28), breast cancers (HR100mSv 1.11; 90% CI 1.05–1.20), and all cancers (HR100mSv 1.05; 90% CI 1.0–1.08, P=0.04). Women with an initial age of exposure lower than 20 were shown with dose response increase in breast cancers risks (HR100mSv 1.38; 90% CI 1.14–1.60; P=0.0008).
Radiation exposure before age 20 was associated with a significantly increased risk of breast cancer at much lower radiation exposure than observed previously.

response [Erroneous] 30 years follow-up and increased risks of breast cancer and leukaemia after long-term low-dose-rate radiation exposure Mark Miller; Scientists for Accurate Radiation Information; 11 Oct 2017

An update on the irradiated Taiwan apartment resident data was published in British Journal of Cancer a week ago by Hsieh, et al. https://www.nature.com/bjc/journal/vaop/ncurrent/pdf/bjc2017350a.pdf . The conclusion of this publication is similar to that of the (Hwang, 2008) publication.
The (Hsieh, 2017) publication claims increased hazard ratios for breast cancer and leukemia using LNT model based analysis of the cancer data (using 90% confidence intervals) – a conclusion that is similar to that of (Hwang, 2008) publication. However, if we examine the total number of cancers observed, and compare to expected number of cancers, estimated using age dependence of cancer rates in Taiwan cancer registry, relative risk is calculated to be 0.83 (with 95% C.I. being 0.73 to 0.94). Their use of the LNT model for analysis allows them to hide this hormetic decrease in overall cancers.
The publication also claims younger irradiated subjects (age < 20) have a higher risk of cancer but this conclusion is based on low statistics (a few cancers).
So, the misinformation campaign continues.

Hwang 2006

Cancer risks in a population with prolonged low dose-rate gamma-radiation exposure in radiocontaminated buildings, 1983-2002. Hwang SL, Guo HR, Hsieh WA, Hwang JS, Lee SD, Tang JL, Chen CC, Chang TC, Wang JD, Chang WP; International Journal of Radiation Biology; Dec 2006

To assess cancer risks in a population that received prolonged low dose-rate gamma-irradiation for about 10 years as a result of occupying buildings containing 60Co-contaminated steel in Taiwan.
The cancer risks were compared with those populations with the same temporal and geographic characteristics in Taiwan by standardized incidence ratios (SIR), adjusted for age and gender. The association of cancer risks with excess cumulative exposure was further evaluated for their relative risks by the Poisson multiple regression analysis.
A total of 7271 people were registered as the exposed population, with 101,560 person-years at risk. The average excess cumulative exposure was approximately 47.8 mSv (range < 1 - 2,363 mSv). A total of 141 exposed subjects with various cancers were observed, while 95 developed leukemia or solid cancers after more than 2 or 10 years initial residence in contaminated buildings respectively. The SIR were significantly higher for all leukemia except chronic lymphocytic leukemia (n = 6, SIR = 3.6, 95% confidence interval [CI] 1.2 - 7.4) in men, and marginally significant for thyroid cancers (n = 6, SIR = 2.6, 95% CI 1.0 - 5.7) in women. On the other hand, all cancers combined, all solid cancers combined were shown to exhibit significant exposure-dependent increased risks in individuals with the initial exposure before the age of 30, but not beyond this age.
The results suggest that prolonged low dose-rate radiation exposure appeared to increase risks of developing certain cancers in specific subgroups of this population in Taiwan.

Hwang 2008

Estimates of relative risks for cancers in a population after prolonged low-dose-rate radiation exposure: a follow-up assessment from 1983 to 2005. Hwang SL1, Hwang JS, Yang YT, Hsieh WA, Chang TC, Guo HR, Tsai MH, Tang JL, Lin IF, Chang WP.; Radiation Research; Aug 2008

Radiation effects on cancer risks in a cohort of Taiwanese residents who received protracted low-dose-rate gamma-radiation exposures from (60)Co-contaminated reinforcing steel used to build their apartments were studied, and risks were compared to those in other radiation-exposed cohorts. Analyses were based on a more extended follow-up of the cohort population in which 117 cancer cases diagnosed between 1983 and 2005 among 6,242 people with an average excess cumulative exposure estimate of about 48 mGy. Cases were identified from Taiwan's National Cancer Registry.
Radiation effects on cancer risk were estimated using proportional hazards models and were summarized in terms of the hazard ratio associated with a 100-mGy increase in dose (HR(100mGy)). A significant radiation risk was observed for leukemia excluding chronic lymphocytic leukemia (HR(100mGy) 1.19, 90% CI 1.01-1.31). Breast cancer exhibited a marginally significant dose response (HR(100mGy) 1.12, 90% CI 0.99-1.21). The results further strengthen the association between protracted low-dose radiation and cancer risks, especially for breast cancers and leukemia, in this unique cohort population.

A response by medical physicist Mohan Doss challenges the 2006 and 2008 Hwang et al papers' conclusions An Analysis of Irradiated Taiwan Apartment Residents' Cancer Incidence Data Mohan Doss; blog; 10 Sep 2013

Whereas the most significant result (with most statistics) was that the overall cancer rate (or solid cancer rate) was significantly lower in the radiated population, the abstract does not even mention it! By slicing the data into smaller subgroups (with poorer statistics), the authors pointed out in the abstract whenever the cancer rates were elevated.

Chen 2007

Effects of Cobalt-60 Exposure on Health of Taiwan Residents Suggest New Approach Needed in Radiation Protection W.L. Chen, Y.C. Luan, M.C. Shieh, S.T. Chen, H.T. Kung, K.L Soong, Y.C. Yeh, T.S. Chou, S.H. Mong, J.T. Wu, C.P. Sun, W.P. Deng, M.F. Wu, M.L. Shene; Dose Response; Aug 2006

The conventional approach for radiation protection is based on the ICRP's linear, no threshold (LNT) model of radiation carcinogenesis, which implies that ionizing radiation is always harmful, no matter how small the dose. But a different approach can be derived from the observed health effects of the serendipitous contamination of 1700 apartments in Taiwan with cobalt-60 (T1/2 = 5.3 y). This experience indicates that chronic exposure of the whole body to low-dose-rate radiation, even accumulated to a high annual dose, may be beneficial to human health. Approximately 10,000 people occupied these buildings and received an average radiation dose of 0.4 Sv, unknowingly, during a 9–20 year period. They did not suffer a higher incidence of cancer mortality, as the LNT theory would predict. On the contrary, the incidence of cancer deaths in this population was greatly reduced—to about 3 per cent of the incidence of spontaneous cancer death in the general Taiwan public. In addition, the incidence of congenital malformations was also reduced—to about 7 per cent of the incidence in the general public. These observations appear to be compatible with the radiation hormesis model. Information about this Taiwan experience should be communicated to the public worldwide to help allay its fear of radiation and create a positive impression about important radiation applications. Expenditures of many billions of dollars in nuclear reactor operation could be saved and expansion of nuclear electricity generation could be facilitated. In addition, this knowledge would encourage further investigation and implementation of very important applications of total-body, low-dose irradiation to treat and cure many illnesses, including cancer. The findings of this study are such a departure from expectations, based on ICRP criteria, that we believe that they ought to be carefully reviewed by other, independent organizations and that population data not available to the authors be provided, so that a fully qualified epidemiologically-valid analysis can be made. Many of the confounding factors that limit other studies used to date, such as the A-bomb survivors, the Mayak workers and the Chernobyl evacuees, are not present in this population exposure. It should be one of the most important events on which to base radiation protection standards.

Chen 2004

2004 Chen, Is Chronic Radiation an Effective Prophylaxis Against Cancer W.L. Chen, Y.C. Luan, M.C. Shieh, S.T. Chen, H.T. Kung, K.L. Soong, Y.C. Yeh, T.S. Chou, S.H. Mong, J.T. Wu, C.P. Sun, W.P. Deng, M.F.Wu, M.L. Shen; Journal of American Physicians and Surgeons; Spring 2004

An extraordinary incident occurred 20 years ago in Taiwan. Recycled steel, accidentally contaminated with cobalt-60 (half-life: 5.3 y), was formed into construction steel for more than 180 buildings, which 10,000 persons occupied for 9 to 20 years. They unknowingly received radiation doses that averaged 0.4 Sv—a “collective dose” of 4,000 person-Sv.
Based on the observed seven cancer deaths, the cancer mortality rate for this population was assessed to be 3.5 per 100,000 person-years. Three children were born with congenital heart malformations, indicating a prevalence rate of 1.5 cases per 1,000 children under age 19.
The average spontaneous cancer death rate in the general population of Taiwan over these 20 years is 116 persons per 100,000 person-years. Based upon partial official statistics and hospital experience, the prevalence rate of congenital malformation is 23 cases per 1,000 children. Assuming the age and income distributions of these persons are the same as for the general population, it appears that significant beneficial health effects may be associated with this chronic radiation exposure.
The findings of this study are such a departure from expectations, based on International Commission on Radiological Protection (ICRP) criteria, that we believe that they ought to be carefully reviewed by other, independent organizations and that population data not available to the authors be provided, so that afully qualified, epidemiologically valid analysis can be made. Many of the confounding factors that limit other studies used to date, such as those of the A-bomb survivors, the Mayak workers, and theChernobyl evacuees, are not present in this population exposure. It should be one of the most important events on which to base radiation-protection standards.
The data on reduced cancer mortality and congenital malformations are compatible with the phenomenon of radiation hormesis, an adaptive response of biological organisms to low levels of radiation stress or damage–a modest overcompensationto a disruption–resulting in improved fitness. Recent assessments of more than a century of data have led to the formulation of a wellfounded scientific model of this phenomenon.
The experience of these 10,000 persons suggests that longterm exposure to radiation, at a dose rate of the order of 50 mSv (5 rem) per year, greatly reduces cancer mortality, which is a major cause of death in North America. Medical scientists and organizations may wish to seriously assess this and other current evidence in deciding whether chronic radiation could be an effective agent for enhancing defenses against cancer.


Radiation Hormesis, Cancer, and Freedom in American Medicine Arthur B. Robinson, Ph.D.; Journal of American Physicians and Surgeons; Fall 2013

In 1983, a group of apartment buildings was completed in Taipei City, Taiwan. Recycled steel contaminated with cobalt-60 was accidentally used in the construction materials. Cobalt-60 is radioactive, with a half-life of 5.3 years.
People lived in these buildings for between 9 and 20 years. As of 2011, many still did. In 1992, a higher-than-normal radiation level was discovered in some of the apartments.
Over the period between 1992 and 1998, higher-than-normal radiation was found in increasing numbers of structures until buildings used by 10,000 people were found to be involved.
As would be expected, Taiwanese officials scrambled to test for cancer and birth defects in the people living in these apartments. The government of Taiwan was very embarrassed by these events and even more distressed by the medical results, which are summarized in Figure 1. This figure shows the cancer mortality between 1993 and 2002 for these apartment dwellers and for the general population in Taiwan.

Taiwan Cancer Mortality of General v Exposed Population.png


Compelling Reasons for a Paradigm Shift in Radiation Safety and Revised Health Physics Goals Mohan Doss; Conference paper: Meeting of the New Jersey Chapter of the Health Physics Society; Sept 2014

The current radiation safety paradigm is based on the linear no-threshold (LNT) hypothesis. The absence of threshold dose has led to fear of the smallest amount of radiation and has caused tremendous harm in multiple ways. Is the LNT hypothesis validated by the evidence? On examining the evidence for and against the LNT hypothesis, it becomes clear that considerable amount of evidence supports the concept of radiation hormesis, i.e., reduction of cancers from low-dose radiation (LDR) or a threshold dose-response, i.e. no increase in cancers from LDR. On the other hand, major flaws have led to the negation of the evidence commonly quoted in support of the LNT hypothesis. The scientific conclusion from analyzing all the evidence is that LDR reduces cancers. Thus, the radiation safety paradigm must be changed. The present health physics goals, focused as they are on radiation safety, do not address the current main health concerns of the public, i.e. the lack of progress in dealing with major diseases like cancer and Alzheimer's disease (AD). Also, the aspirations of the world population for improved living standards is increasing the use of fossil fuels resulting in increased degradation of the environment, harming public health. A change in radiation safety paradigm that recognizes the presence of a threshold dose for radiation-induced cancers would reduce the fear of LDR and enable increased use of safer nuclear power. It would also enable study of LDR for prevention of cancer and other aging-related diseases like AD, for which animal models have shown promise. A revision of health physics goals is suggested changing the focus to improving health with the safe use of radiation.

Fellman 2016 (presentation)

Putting Radiation Risks from NORM Into Perspective Alan Fellman, Ph.D., C.H.P.; Marcellus Shale Coalition Meeting; 26 Oct 2016

Topics for Discussion
  • Typical radiation levels at oil and gas facilities
  • Radiological Health Risk – perception vs. reality
  • LNT and ALARA
  • What it all means for our health and safety programs

Doss et al

Radiation Hormesis Should be the Basis for Establishing Radiation Protection Standards Mohan Doss et al; Comments to EPA; 14 May 2017

The Taiwan Question Al Tschaeche CHP Health Physics News May 2005.jpg

High Background Radiation study

Evidence for adaptive response in a molecular epidemiological study of the inhabitants of high background radiation area of Yangjiang in China Shibiao Su et al; Health Physics; Aug 2018

Dr Su and colleagues report observing improved DNA damage repair and antioxidant capacity and reduced rates of cell-suicide in inhabitants of the high background radiation area (HBRA) compared to a control area with lower background radiation. Dr. Su notes that these results are consistent with their previous results observing lower rates of cancer mortality in the inhabitants of the HBRAs
Our previous studies have shown that cancer mortality in high background-radiation areas of China was lower than that in a control area, indicating the possibility of an adaptive response in high background-radiation areas. Our aim is to determine the effect of low-dose radiation on the level of DNA oxidative damage, DNA damage repair, antioxidant capacity, and apoptosis in high background-radiation area and control area populations of Guangdong through a molecular epidemiological study in order to identify adaptive response. Blood samples were collected from male residents aged 50 to 59 y in a high background-radiation area (Yangjiang) and a control area (Enping), and activities of superoxide dismutase, glutathione, catalase, total antioxidant capacity, and expression of O6‐methylguanine-DNA methyltransferase gene (MGMT), human 8‐oxoguanine DNA N-glycosylase 1 gene (hOGG1), proapoptotic genes and antiapoptotic genes, oxidative-stress-related genes, as well as concentrations of 8‐OHdG, TrxR, HSP27, and MT-COX2 were determined. The activities of antioxidative enzymes, relative mRNA expression level of DNA repair genes, antiapoptotic genes, oxidative-stress-related genes HSPB1 and MT-COX2, and the concentration of antioxidant index TrxR in the high background-radiation area population increased significantly compared to the control population (p < 0.05). The relative mRNA expression level of proapoptotic genes and the concentration of DNA oxidative damage index 8‐OHdG were significantly lower in the high background-radiation area compared to those in the control area (p < 0.05). In conclusion, under long-term, natural, high background, ionizing radiation, DNA damage-repair capacity and antioxidant capacity of inhabitants in the high background-radiation area may be enhanced. Additionally, it could induce up regulation of cell-survival gene expression and down regulation of apoptotic gene expression. It might be speculated that enhanced antioxidant and DNA repair capacity and inhibition of apoptosis might play important roles in adaptive response of low-dose radiation in high background-radiation areas.

regulation reform

Time to Reject the Linear-No Threshold Hypothesis and Accept Thresholds and Hormesis: A Petition to the U.S. Nuclear Regulatory Commission Marcus CS; Clinical Nuclear Medicine; Jul 2015 (Paywalled - link to content)

On February 9, 2015, I submitted a petition to the U.S. Nuclear Regulatory Commission (NRC) to reject the linear-no threshold (LNT) hypothesis and ALARA as the bases for radiation safety regulation in the United States, using instead threshold and hormesis evidence. In this article, I will briefly review the history of LNT and its use by regulators, the lack of evidence supporting LNT, and the large body of evidence supporting thresholds and hormesis. Physician acceptance of cancer risk from low dose radiation based upon federal regulatory claims is unfortunate and needs to be reevaluated. This is dangerous to patients and impedes good medical care. A link to my petition is available: http://radiationeffects.org/wp-content/uploads/2015/03/Hormesis-Petition-to-NRC-02-09-15.pdf, and support by individual physicians once the public comment period begins would be extremely important.

Linear No-Threshold Model and Standards for Protection Against Radiation Federal Register (The Daily Journal of the United States Government)

A Proposed Rule by the Nuclear Regulatory Commission on 06/23/2015
The U.S. Nuclear Regulatory Commission (NRC) has received three petitions for rulemaking (PRM) requesting that the NRC amend its “Standards for Protection Against Radiation” regulations and change the basis of those regulations from the Linear No-Threshold (LNT) model of radiation protection to the radiation hormesis model. The radiation hormesis model provides that exposure of the human body to low levels of ionizing radiation is beneficial and protects the human body against deleterious effects of high levels of radiation. Whereas, the LNT model provides that radiation is always considered harmful, there is no safety threshold, and biological damage caused by ionizing radiation (essentially the cancer risk) is directly proportional to the amount of radiation exposure to the human body (response linearity). The petitions were submitted by Carol S. Marcus, Mark L. Miller, and Mohan Doss (the petitioners), dated February 9, 2015, February 13, 2015, and February 24, 2015, respectively. These petitions were docketed by the NRC on February 20, 2015, February 27, 2015, and March 16, 2015, and have been assigned Docket Numbers. PRM-20-28, PRM-20-29, and PRM-20-30, respectively. The NRC is examining the issues raised in these petitions to determine whether they should be considered in rulemaking. The NRC is requesting public comments on these petitions for rulemaking.